Abstract
Objective Changes in postmenopausal hormone levels are associated with a
variety of disorders. This study elucidated the mechanism by which
follicle-stimulating hormone (FSH) increases cortisol production involved in
development of menopause-related diseases.
Methods The expression of FSH receptors (FSHRs) in murine adrenal zona
fasciculata (AZF) cells and ATC7 cells was verified by immunofluorescence,
western blotting and RT–PCR. The function of FSHR in promoting cortisol
production was analyzed by cell culture and molecular biological methods. FSHR
signaling pathways in ATC7 cells were analyzed by ELISA, qRT–PCR, and western
blotting. Further, a mouse model was established by ovariectomy. Ovariectomized
mice were treated with GnRHa. Ovariectomized mice initially received
physiological doses of estrogen and were then injected with recombinant FSH.
Then serum FSH, luteinizing hormone (LH), estradiol, and cortisol, and bone
mineral density (BMD), blood pressure (BP) and heart rate (HR) were
determined.
Results FSHRs were expressed in murine AZF cells and ATC7 cells. FSH
accelerated cortisol production through activated protein kinase A (PKA), cyclic
adenosine monophosphate (cAMP)-response element binding protein (CREB), protein
kinase B (PKB/AKT) and 5ʼ AMP-activated protein kinase (MAPK) signaling pathways
by Gsα-coupled FSHRs in ATC7 cells. Serum FSH levels (P<0.001) were
elevated in ovariectomized mice with concurrent increases in cortisol
(P<0.01), areal BMD (aBMD) (P<0.05), volumetric BMD
(vBMD) (P<0.05), systolic BP (SBP) (P<0.05), diastolic BP
(DBP) (P<0.05), and HR (P<0.05). However, the administration
of GnRHa suppressed the increase in FSH levels and the elevation of cortisol,
aBMD, vBMD, SBP, DBP, and HR induced by ovariectomy, even in the presence of
normal serum estradiol levels.
Conclusion The study findings indicate that elevated FSH levels stimulate
cortisol secretion, through a mechanism related to FSHRs expression in AZF
cells.